Earlier quoted context omitted.
> Imagine Facebook disappearing with your list of friends, or Google Docs with your documents. Yes, I imagine it on a daily basis. That's how the cloud works. It's happened before, and it will happen again. Any cloud based data is bound to disappear at any second because of a hack (ask Matt Hunan), because of a court order you are not aware of, because of an in-court-or-out-of-court settlement you are not part of and…
Do you keep a backup of your list of Facebook friends, your HN posts and "saved stories"?
Whenever there's an interesting story on HN I think I'd want to refer to later, I bookmark&cache it locally.
And posts/comments I deem worthy to save, I do save a copy of locally, although that's about one in fifty I make.
I know that's not common, and furthermore in the event of a global facebookgeddon, it is likely my bookmarks would be useless. But in the case of a local cloudgeddon (see e.g. the Matt Hunan story), I'm mostly covered.